Gas insulated switch with adjustable overcenter toggle actuator therefore

ABSTRACT

An improved switch construction is provided having associated therewith an improved overcenter spring mechanism, which has a lost-motion connection with the lever assembly for actuating the contact shaft of the switch. The construction is such that a driving motor is used to move the overcenter spring assembly to an overcenter position, at which time it moves over-toggle, and quickly effects opening or closing movements of the lever assembly, the latter driving the contact-operating shaft at its free end. An auxiliary feature of the invention provides an in-toggle arrangement at the end of the opening and closing operations of the movable contact shaft by the use of a cam-coupling, interconnecting the end of the contact-operating shaft with the end of the free end of the operating lever. As a further auxiliary feature of the invention, the switch construction and its associated mechanism are particularly adaptable for use in gas-insulated substations, of the type in which transmission of power occurs through an enclosed gasinsulated bus, capable, for example, of voltages of 46 KV through 500 KV, with a highly-insulating gas, such as sulfur-hexafluoride (SF6) gas at a suitable pressure, such as 45 p.s.i.g. The switch, however, is capable of application in other environments.

United States Patent 1191 Spindle et al.

1451 Feb. 26, 1974 GAS INSULATED SWITCH WITH ADJUSTABLE OVERCENTER TOGGLE' ACTUATOR THEREFORE [75] Inventors: Harvey E. Spindle; Jeffry R. Meyer,

both of Pittsburgh; Robert L. Hess,

North Versailles, all of Pa.

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

221 Filed: Mar. 27, 1972 21 Appl. No.: 238,381

[52] US. Cl. 200/153 G, 200/148 B, 200/163,

335/68 [51] Int. Cl H0111 3/46, HOlh 3/26, HOlh 33/36 [58] Field of Search..........200/163,153G, 153 SC,

200/153 LA,67 PK, 148 B, 153 H, 153 v; 335/189, 68,76

[56] References Cited UNITED STATES PATENTS 3,654,409 4/1972 Kessler 200/163 X 2,905,787 9/1959 Heintz 335/76 X 3,236,967 2/1966 Bottonari et a1 335/76 X 2,430,008 11/1947 Fernier 200/153 V UX FORElGN PATENTS OR APPLlCATlONS 1,474,847 3/1967 France 200/163 1,371,871 8/1964 France 200/148 B Primary E J a n 'ner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney, Agent, or Firm-W. R. Crout 5 7 ABSTRACT An improved switch construction is provided having associated therewith an improved overcenter spring mechanism, which has a lost-motion connection with the lever assembly for actuating the contact shaft of the switch. The construction is such that a driving motor is used to move the overcenter spring assembly to an overcenter position, at which time it moves overtoggle, and quickly effects opening or closing movements of the lever assembly, the latter driving the contact-operating shaft atits free end.

An auxiliary feature of the invention provides an iii-toggle arrangement at the end of the opening and closing operations of the movable contact shaft by the use of a cam-coupling, interconnecting the end of the contact-operating shaft with the end of the free end of the operating lever.

As a further auxiliary feature of the invention, the switch construction and its associated mechanism are particularly adaptable for use in gas-insulated substations, of the type in which transmission of power occurs through an enclosed-gas-insulated b'us, capable, forexainple, of voltages of 46 KVthrou'gh5TT RV, with a highly-insulating gas, such as sulfur-hexafluoride (SP gas at a suitable pressure, such as 45 p.s.i.g. The switch, however, is capable of application in other environments.

I 16 Claims, 13 Drawing Figures PATENTEUFEB26 .9 3794.799

FIG. I

SHEET 2 OF 6 PATENTEU FB26 197 PATENTEn Faazs m4 3.794' 799 SHEET 3 OF 6 PATENTEI] FEB 26 I974 SHEET t 0F 6 PATENTEDFEBZG mm SHEET 5 BF 6 1 GAS INSULATED SWITCH WITH ADJUSTABLE OVERCENTER TOGGLE ACTUATOR THEREFORE CROSS-REFERENCES TO RELATED APPLICATIONS Reference may be made to United States Pat. application filed Mar. 22, 1972, Ser. No. 237,079, entitled Grounding Switch, by Jeffery R. Meyer (WE 43,359), and assigned to the assignee of the instant application, which shows a grounding-switch application, as particularly applied to a gas-insulated transmission system.

BACKGROUND OF THE INVENTION In recent years, there has come about a demand for a reduced-size substation, and this demand, on the part of public utilities, has been met by gas-insulated substation equipment, such as set forth in United States Pat.

Nos. 3,378,731 Whitehead; 3,361,870 Whitehead;

3,356,798 McKinnon; 3,348,001 Upton et a1; 3,345,450 Spindle; 3,324,272 Shankle et a1; 2,173,717 Hobart; 3,610,858 Gruber et al; 3,599,041 Boersma et al.

The foregoing equipment significantly reduces the space required by the high-voltage side of substations rated, for example, 46 KV through 500 KV. The space reduction is accomplished by replacing the open-bus and air-type bushings with gas-insulated bus filled, for example, with a highly-insulating gas, such as sulfurhexafluoride (SP gas, at a pressure say, for example, 45 p.s.i.g., and thereby permitting the movement of electrical equipment very closely together. This gasinsulated sub-station equipment has many advantages,

among which are:

l. Significant reduction in space requirements both in land area and overall height.

2 Added system reliability by eliminating the possibility of phase-to-phase faults, lightning strokes within the system, or contamination of insulators.

3. Reduced maintenance because the closed system is isolated from its environment.

4. Added personnel safety because all live parts are covered by grounded shields.

5. The gas-insulated modular approach has the additional advantage, because it provides the user with lower installation costs, when compared with conventional, or other types of power systems.

The gas-insulated system, as briefly described above, has additional design strategies, inasmuch as the highvoltage equipment is compressed, so that both the space required, and the total length of bus is minimized. The power transformers may be located on outside corners so as to be capable of ready removal, and the location of cable potheads is flexible, with the result that the system may be readily connected to overhead lines.

As examples of the types of ratings for such gasinsulated transmission systems, reference may be made to the specification ratings, as set forth below:

115/ 1 38Ikv Ratings General Ratings for MGT Systems SF, at 45 psig Rated maximum voltage 1 145 Load break switch BIL 60 H2 one minute withstand Chopped wave 650 3 10 Not applicable lsolator Ground switch No load switching only No load switching only Continuous Current Ratings Circuit breaker 2500 Amperes 2500 Amperes Magnetizing current switch 2500 Amperes lsolator 2500 Amperes Ground Switch Not applicable Bus 3000 Amperes 230 kv Ratings General Ratings for MGT Systems SF at 45 psig Rated maximum voltage 242 BIL 900 60 HZ one minute withstand 425 Chopped wave Not applicable Symmetrical 3 Second Current Rating 47 ka Momentary Current 76 ka Switching Current Ratings Circuit breaker (maximum rated interrupting current) 50 ka Magnetizing current switch 35 amps lsolator No load switching only Ground switch No load switching only Continuous Current Ratings Circuit breaker 2500 Amperes Load break switch 2500 Amperes Magnetizing current switch 2500. Amperes lsolator 2500 Amperes Ground switch Not applicable Bus 3000 Amperes 345 kv Ratings General Ratings for MGT Systems SF at 45 psig Rated maximum voltage 362 BlL 1050 60 HZ one minute withstand 555 Chopped wave Not applicable Symmetrical 3 Second Current Rating 47 ka Momentary Current 76 ka Switching Current Ratings Circuit breaker (maximum rated interrupting current) 50 ka Magnetizing current switch 35 amps lsolator Ground Switch No load switching only No load switching only Continuous Current Ratings Circuit breaker Load break switch Magnetizing current switch 2500 Amperes 2500 Amperes 2500 Amperes lsolator 2500 Amperes Ground Switch Not applicable Bus 3000 Amperes SUMMARY OF THE INVENTION struction is such that a remotely controlled electrical driving motor is associated with the overcenter-spring mechanism, so as to have a lost-motion connection therewith, so that the contact structure is maintained in its open or closed positions until the overcenter-spring mechanism attains its overcenter position, at which time the contact structure is rapidly moved to its other 7 position. The mechanism is adaptable for quickly moving the contact shaft to either the open or closed-circuit positions, as desired, inasmuch as the driving motor is reversible.

Accordingly, it is a general object of the present invention to provide an improved switch construction having an overcenter-spring mechanism associated therewith to provide quick-opening and closingmotions of the switch assembly.

Still a further object of the present invention is the provision of an improved switch having an electrically driven driving motor, the latter havinga lost-motion connection with an overcenter-spring mechanism, so that although the motor shaft may move relatively slowly, nevertheless, upon the attainment of an overcenter position for the overcenter spring mechanism, a quick-opening, or closing movement is achieved.

Still a furtherobject of the present invention is the provision of an improved switch mechanism for a gasinsulated transmission system capable of interrupting transformer magnetizing currents, such, for example, as 35 amper'es.

Still a further object of the present invention is the provision of an improved magnetizing-current switch for a gas-insulated substation to provide sectionalizing of various portions of the gas-insulated system.

Another object of the present invention is the provision of'an improved overcenter spring mechanism for a switch, in which the switch is maintained in an overtoggle position in both its opened and closed-circuit positions of the switch structure.

Another object of the present invention is the provision of an improved cam-coupling arrangement for the rotatable-operating lever assembly for a contact shaft, so as to, in effect, lock the contact shaft in either its open or closed-circuit positions.

Still a further object of the present invention is to provide an improved magnetizing-current switch for a gas-insulated substation in which the switching compartment is isolated from the remainder of the system to prevent the transmission of contaminated gas along the transmission system, in which barrier discs are utilized at a T intersection, with a suitable location of the rotatable contact-crank assembly within a sealed adjacently-disposed housing.

Still a further object of the present invention is the provision of improved magnetizing-current switch for a gas-insulated substation in which a shock absorber, or cushioning device, is provided to cushion the shock o the opening operation of the switch.

Further objects and advantages will readily become apparent upon reading the following.specification;

taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagrammatic view of a gasinsulated substation showing the gneral environment for one application of the magnetizing-current switch of the present invention;

FIG. 2 is a one-line diagram for the gas-insulated substation .of FIG. 1;

FIG. 3 is a longitudinal vertical sectional view taken through the improved switch construction of the present invention, as particularly applied to a gas-insulated substation, with the contact mechanism illustrated in its closed-circuit position;

FIG. 4 is a sectional view taken substantially along the line IV-IV of FIG. 3, drawn to an enlarged scale;

FIG. 5 is an end elevational view of the overcenterspring mechanism, taken substantially along the line V-V of FIG. 3, looking in the direction of the arrows;

FIG. 6 is an enlarged fragmentary vertical-sectional view taken through the overcenter spring mechanism, substantially along the line VI-VI of FIG. 5, but the contact-operating shaft being shown in its fully openedcircuit position;

FIGS. 7 and 8 are side and end views of the T-shaped overcenter-toggle link for the overcenterspring mechanism of the present invention; y 7

FIG. 9 is a longitudinal sectional view of the operating contact-shaft assembly;

FIGS. 10 and 11 are side and end views of the camcoupling to be secured to the free end of the movable contact-shaft assembly; 7 I

FIG. 12 is an enlarged plan view of the couplingbetween the driving motor and the overcenter springlever assembly; and,

FIG. 13 is an enlarged fragmentary sectional view of the dashpot assembly, illustrating its conjoint use with the movable contact-operating shaft.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention has particular application to a new line of equipment 1 involving gas-insulated substations having gas-insulated components, and somewhat diagrammatically illustrated in FIGS. 1 and 2 of the drawings.

7 FIG. 2 is a one-line diagram of the equipment 1 illustrated in FIG. 1. It will be noted, from a consideration of FIGS. 1 and 2, that the high-voltage equipment 1 is arranged so that both the space required, and the total a length of the gas-insulated bus 3 is minimizedfThe power transformer 4 is located on an outside corner, preferably, so that it can be easily removed. The gasinsulated bus 3 is attached directly to the transformer bushing minimizing area and height required. The location of the cable pothead is flexible. In the gas-insulated system 1, as illustrated in FIGS. 1 and 2, it is chosen to The gas-insulated transmission system 1 illustrated in FIG. 1 is a line of equipment, which will significantly reduce the space required by the high-voltage side of substations rated 115 KV through 345 KV. The space reduction is accomplished by replacing the open bus and air bushings, commonly used, with gas-insulated bus 3 filled with sulfur-hexafluoride (SF gas, for example, at 45 p.s.i.g. (at 70 F.), and moving the electrical equipment as close together as possible.

The use of gas-insulated transmission systems 1 offers many advantages. The use of the MGT System offers several advantages to the user; some of these are:

l. Significant reduction in space requirement both coupling between land area and overall height.

2. Added system reliability by eliminating the possibility of phase to phase faults, lightning strokes within the system or contamination of environment.

3. Reduced maintenance because of the closed system is isolated from its environment.

4. Added personnel safety because all live parts are covered by grounded shields.

5. The modular approach described in the following section was chosen because it could provide the user with lower installation costs when compared with conventional or other gas insulated systems.

6. The system can be overbuilt to permit multiple use of land.

Generally, the equipment 1 includes a plurality of bus assemblies determined by the length that can generally be shipped. The typical bus length 3 will be, for example, 40 feet, and may consist of two 20-feet lengths, with an epoxy spacer 9 in each length. the ends of the bus 3 can be connected to additional lengths of bus, or any functional member of the system. Expansion joints are located in each ZO-feet bus section 3 to absorb the maximum of 0.4 inches of expansion expected. As stated, sulfur-hexafluoride (SP gas at 45 p.s.i.g., for example, fills both sheath l1 and bus conductor 13, and is free to move throughout the entire'bus. The 45 p.s.i.g. pressure provides approximately the highest dielectric strength possible down to 40C. without liquefaction, eliminating the need for auxiliary heat. The 45 p.s.i.g. pressure also eliminatesthe possibility of stable corona existing within the system 1.

The present invention is particularly concerned with a magnetizing-current switch 16, illustrated in FIGS. '3-6 of the drawings. With reference to these figures, it will be noted that there is provided a gas-insulated bus, or.high-voltage metallic conductor, designated by the reference 1-3.

It will be noted that the high-voltage central conductor 13 is spaced coaxially along the outer metallic grounded sheath, or cylinder 11 by a plurality of suitably spaced insulating spacers, designated by the reference numeral 9, two of which are illustrated in FIG. 3

I of the drawings. As will be obvious to those skilled in -movable conducting bridging contact 18, which is opened and closed by an operating-shaft assembly, generally designated by the reference numeral 20, and actuated byan overce'nter-spring mechanism, designated 6 by the reference numeral 22, and illustrated more clearly in FIGS. 5 and 6 of the drawings.

Since the movable bridging conductor 18 is at high voltage, at times it is necessary to insulate it from the grounded outer sheath ll of the equipment, and to effect this end an insulating-rod assembly, designated by the reference numeral 24, is utilized andinterposed between the movable conductor 18 and the operating shaft, designated by the reference numeral 20. To cushion the opening operation at the end of the opening stroke, a suitable dashpot 26, illustrated in FIG. 13, and comprising a spring-biased piston 26a, picked up by a ring 28, movable with the movable operating shaft 24, cushions the opening stroke in a manner, which appears obvious from FIG. 13 of the drawings. The lefthand end of the operating-rod shaft 24 is provided with a horizontal pin, designated by the reference numeral 30 (FIG. 4), and sliding in two spaced horizontal guide slots 32 provided in a pair of plate members 34, 35 FIGS. 3 and 4 rigidly affixed interiorly of an enclosed mechanism housing 36, and illustrated more clearly in FIGS. 3 and 6 of the drawings.

Additionally, the left-hand end of the operating contact shaft 24 has a slotted cam plate 38 affixed thereto. FIGS. 10 and 11 of the drawings illustrate detailed views of the cam plate 38 and the thimble 38a welded thereto, the thimble 38a having a threaded bore 38b, which is threadedly secured to the left-hand end 240 (FIG. 4) of the operating shaft 24, as illustrated in FIGS. 4 and 6 of the drawings. Thus, in the fully open and closed-circuit positions of the magnetizing switch 16, it will be observed that the bridging-contact structure 18 is locked or in toggle, reference being had to FIGS. 3 and 6 in this connection. A contactoperating lever 40, pinned to a horizontally extending operating shaft 44, has the free end 40a thereof pinned to a roller 46, which moves within the cam slot 48 .(FIG. 10) provided by the cam member 38. FIG. 6 illustrates the connection of the parts more clearly.

As mentioned, the contact-operating lever 40 is fixedly secured to the operating shaft 44, this preferably being accomplished by squaring the center portion 44a of the shaft 44, and passing it through a square hole in the rotatable operating lever 40. This rotation, of course, is effected interiorly within the closed mechanism housing 36, inasmuch as gas pressure is present therein.

Theoperating shaft 44 has smooth round ends 44b, which pass through bearings 50 and 51 (FIG. 4), with one end 440 of the operating shaft 44 extending externally of the mechanism housing 36, and being pinned to an operating lever, designatd by the reference numeral 54. As shown in FIGS. 3 and 6, the externally located operating lever 54 has a lost-motionconnection with a generally T-shaped overcenter three-legged toggle-link member, designated by the reference numeral 57, and illustrated more clearly in FIGS. 7 and 8 of the drawings. The externally-disposed operating lever 54 has a pair of adjustable abutment means 54a, 54b,

which provide ready external-adjustment to'control the amount of lost-motion between the three-legged toggle 57 and the operating lever 54.

' The three-legged T-shaped toggle-link member 57 has rigidly affixed thereto a round stub-shaft portion, designated by the reference numeral 57a, having a transverse pin 59 provided therein. This pin 59 is.

picked up by a notched sleeve coupling 61 (FIG. 12)

rotated by a driving motor or reversible operator 63, the coupling 61 being more clearly illustrated in FIG. of the drawings. Thus, the energization of the operator or driving motor, designated by the reference numeral 63, will effect rotation of the notched coupling 61, and following a certain lost-motion, will pick up the pin 59, thereby effecting clockwise rotation of the three-legged toggle-link member 57, as viewed in FIG. 3, to move it to an overcenter position, at which time the accelerating spring 65 will forcibly move it in a continued clockwise direction, as viewed in FIG. 3, picking up the external operating lever 54 (FIG. 4), which carries the interiorly disposed contact operating lever 40 therewith. Thus, there is a lost-motion connection 69 provided between the coupling 61, rotated by the driving motor or operator 63, and the toggle-link member 57, and there is a second lost-motion 71 interconnection between the toggle-link member 57 and the operating lever 54 for the operating shaft 44.

The accelerating spring 65 is positioned interiorly of a cylindrically shaped rotatable spring housing 72, more clearly illustrated in FIG. 6, and rotatable about an upper pivot pin 73, the latter being supported by two upwardly spaced support plates 75, 76, more clearly illustrated in FIG. 5 of the drawings.

It will be observed that the mechanism housing 36 is completely enclosed, with only the operating shaft 44 extending laterally through a side wall thereof, and sealed to prevent the leakage of gas axially along the operating shaft 44, as illustrated in FIG. 4.

FIG. 9 illustrates the movable contact-operating rod 24 having a metallic portion 24b and an interposed insulating portion, designated by the reference numeral 24c, the latter being threaded into the movable tubular bridging contact 18, as illustrated in FIG. 9.

The operation of the mechanism 22 will effect quickopening and closing movements of the bridging contact 18 to open and closed positions, as illustrated in FIGS. 3 and 6 of the drawings. The open-circuit position of the movable bridging contact 18 is illustrated by the dotted lines 78 in FIG. 3 of the drawings. The full lines in FIG. 3 illustrate the closed-circuit position thereof.

From the foregoing description, it will be apparent that there has been provided an improved overcenter spring mechanism 22 for effecting the rapid opening and closing operations of a switch. Although the switch has been described with particular application to a gasinsulated transmission system 1 for sectionalizing portions thereof, it will be obvious to those skilled in the art that certain features of the overcenter-spring mechanism 22 may have applicability to other environmental surroundings, and may be used say, for example, with an air-break switch. Also, the use of the slotted camend member 38 and the roller 46 affixed to the free end of the internal-operating lever 40, effects a locking in-toggle position of the contact-operating shaft 24 in both the open and closed-circuit positions thereof.

It will be noted that the grounded sheath 11 is closed by an end plate, designated by the reference numeral 80, and secured by bolts 81 to an end flange 83 secured, as by welding, to the left-hand end of the grounded outer cylinder 11. The bus 13, supported by the insulator 9, extends upwardly, as viewed in FIG. 3, to other equipment, as generally indicated in FIGS. 1 and.2 of the drawings.

It will be noted that the electrical driving motor or operator 63 is reversible, so that, at the option of the maintenance man, the motor 63 may be reversed to effect either opening or closing operations of the magnetizing-bridging contact 18, at the desire of the station attendant.

As applied to a gas-insulated transmission substation,

it will be noted that the breaking of magnetizingcurrent, say, for example, 35 amperes, will take place within an enclosed chamber, designated by the reference numeral 36 in FIG. 3, and partitioned off from the remainder of the system by the two insulating discs,

ated by an electrical driving motor 63,and having a.

lost-motion connection 69 therewith. In addition to the toggle-link member 57 having a lost-motion connection 69 with the coupling, rotated by the motor, it has an additional second lost-motion 71 connection with the operating shaft 44 for the movable bridging contact 18.

Fast-opening and achieved.

Although the description has been directed toward a component part, related to a gas-insulated powertransmission system 1, the mechanism 22 and the switch 16 have applicability, generally, as will be well understood by those skilled in the art.

Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made herein by those skilled in the art, without departing from the spirit and scope of the invention.

We claim: 7

l. A gas-insulated transmission-system including means defining a right-angled sealed chamber, an end plate removably secured to one of the sides of said right-angled sealed chamber, a movable-contact operating-rod extending through an aperture provided in said end plate and an overcenter spring-operated mechanism fixedly secured to said end plate (80) and removable therewith.

2. The combinationaccording to claim I, wherein the overcenter toggle mechanism includes a threelegged toggle member, and spring-means having a spring-rod pivotally supported to one of the legs of said three-legged toggle-member, the other twolegs having individual abutments associated therewith for a lostmotion connection to an actuating lever.

3. The combination according to claim 1, wherein a sealed chamber is fixedly secured to said end plate, an operating shaft extends laterally through the side wall of said sealed chamber, and overcenter spring-means closing motions are thereby are provided including a three-legged toggle member- 4. The combination according to claim 3, wherein an internal rotatable operating lever within said sealed chamber is provided having a pivotal connection with one end of the contact operating-rod.

5. In combination, a generally T-shaped sealed switching compartment (36) comprising a portion of a sealed transmission-system, an end-plate closing one leg of the generally T-shaped sealed chamber, an overcenter spring mechanism fixedly secured to said end' plate (80), and means interconnecting said overcenter spring mechanism with an operating rod disposed interiorly within said generally T-shaped sealed chamber.

housing and having two operating levers fixedly se-.

cured thereto one connected internally to said movable contact and the other'located externally of said sealed gas-housing and having adjustable abutment means secured thereto adaptable for adjustment, a three-legged toggle member disposed externally of said sealed gashousing and having two legs adaptable to alternately strike said adjustable abutment means, means defining an over-center spring, the third leg of the three-legged toggle being substantially at right-angles to each of the other two legs and pivotally connected to said overcenter spring, the throw of the over-center spring being substantially 180 from one side to the complete opposite side, said operating shaft being loose on said threelegged toggle, and actuating means including a reversible operator having a lost-motion connection with said three-legged toggle for causing the alternate overcenter actuation thereof, for obtaining quick-opening and quick-closing motions of the movable contact of the switch.

8. The gas-operated switch of claim 7, wherein the separable contact means provided within the sealed gas-housing includes a pair of separable contacts which i are bridged by a movable bridging contact.

9. The gas-operated switch of claim 7, wherein the movable contact is linearly movable and is in substantial toggle relationship with the internal operating lever in the fully-open and closed-circuit positions thereof.

10. The gas-operated switch of claim 7, wherein a pair of guide plates are disposed internally of the gashousing and have guide slots (32) provided therein to guide the linear motion of the movable contact.

11. The gas-operated switch of claim 7, wherein the reversible operator includes a driving motor.

12. The combination of claim 16, wherein the movable contact has a slotted cam plate (38) secured thereto which is cooperable with a roller provided at the free end of the internally-disposed lever.

13. The combination of claim 7, wherein the gas comprises sulfur-hexafluoride (SP gas.

14. The combination of claim 7, wherein a pair of spaced barrier plates isolate the separable contact means within the sealed gas-housing.

15. The combination of claim 7, wherein a shock- I nal operating lever. 

1. A gas-insulated transmission-system including means defining a right-angled sealed chamber, an end plate removably secured to one of the sides of said right-angled sealed chamber, a movablecontact operating-rod extending through an aperture provided in said end plate (80), and an overcenter spring-operated mechanism fixedly secured to said end plate (80) and removable therewith.
 2. The combination according to claim 1, wherein the overcenter toggle mechanism includes a three-legged toggle member, and spring-means having a spring-rod pivotally supported to one of the legs of said three-legged toggle-member, the other two legs having individual abutments associated therewith for a lost-motion connection to an actuating lever.
 3. The combination according to claim 1, wherein a sealed chamber is fixedly secured to said end plate, an operating shaft extends laterally through the side wall of said sealed cHamber, and overcenter spring-means are provided including a three-legged toggle member.
 4. The combination according to claim 3, wherein an internal rotatable operating lever within said sealed chamber is provided having a pivotal connection with one end of the contact operating-rod.
 5. In combination, a generally ''''T''''-shaped sealed switching compartment (36) comprising a portion of a sealed transmission-system, an end-plate closing one leg of the generally T-shaped sealed chamber, an overcenter spring mechanism fixedly secured to said end plate (80), and means interconnecting said overcenter spring mechanism with an operating rod disposed interiorly within said generally T-shaped sealed chamber.
 6. The combination according to claim 5, wherein a sealed switch-operating chamber (36) is provided having both an internal rotatable actuating lever and also an externally-disposed actuating lever (54) operated by said overcenter-spring mechanism.
 7. A gas-operated switch comprising, in combination, a sealed gas-housing having separable contact means provided therein, said separable contact means including a relatively stationary contact and a cooperable movable contact movable into and out of contacting engagement with said relatively stationary contact, an operating shaft extending out of said sealed-gas-housing and having two operating levers fixedly secured thereto one connected internally to said movable contact and the other located externally of said sealed gas-housing and having adjustable abutment means secured thereto adaptable for adjustment, a three-legged toggle member disposed externally of said sealed gas-housing and having two legs adaptable to alternately strike said adjustable abutment means, means defining an over-center spring, the third leg of the three-legged toggle being substantially at right-angles to each of the other two legs and pivotally connected to said over-center spring, the throw of the over-center spring being substantially 180* from one side to the complete opposite side, said operating shaft being loose on said three-legged toggle, and actuating means including a reversible operator having a lost-motion connection with said three-legged toggle for causing the alternate over-center actuation thereof for obtaining quick-opening and quick-closing motions of the movable contact of the switch.
 8. The gas-operated switch of claim 7, wherein the separable contact means provided within the sealed gas-housing includes a pair of separable contacts which are bridged by a movable bridging contact.
 9. The gas-operated switch of claim 7, wherein the movable contact is linearly movable and is in substantial toggle relationship with the internal operating lever in the fully-open and closed-circuit positions thereof.
 10. The gas-operated switch of claim 7, wherein a pair of guide plates are disposed internally of the gas-housing and have guide slots (32) provided therein to guide the linear motion of the movable contact.
 11. The gas-operated switch of claim 7, wherein the reversible operator includes a driving motor.
 12. The combination of claim 16, wherein the movable contact has a slotted cam plate (38) secured thereto which is cooperable with a roller provided at the free end of the internally-disposed lever.
 13. The combination of claim 7, wherein the gas comprises sulfur-hexafluoride (SF6) gas.
 14. The combination of claim 7, wherein a pair of spaced barrier plates isolate the separable contact means within the sealed gas-housing.
 15. The combination of claim 7, wherein a shock-absorber (26) is provided to cushion the opening operation of the movable contact.
 16. The combination according to claim 7, wherein the adjustable abutment means comprises two independent adjustment screws on opposite sides of the external operating lever. 